1. Field of the Invention
This invention relates generally to the transport of a target substance from an earth formation, and may find commercial application in the recovery of hydrocarbons from a wellbore or in environmental clean-up operations.
2. Description of the Prior Art
Hydrocarbons are likely to remain a critical component of this nation's economy. While the oil and gas industry expends considerable sums in the exploration and development of new fields, the industry also recognizes that a large amount of unproduced hydrocarbons remain in formations which have already been discovered and produced. Many older formations have been subjected to workover operations, wherein the hydrocarbon-bearing formations were fractured, water-flooded, and subjected to various chemical treatments. Even in those formations in which substantial sums have been expended on secondary recovery operations, the industry recognizes that substantial deposits remain. This has given rise to a tertiary recovery industry, wherein various techniques are utilized to stimulate the formation and generate the production of additional hydrocarbons therefrom. For example, a variety of techniques exist in which the formation is subjected to electrical or thermal stimulation which allows for the additional production of hydrocarbons. For example, various prior art techniques include the stimulation of the formation using microwave radiation. Alternatively, electrodes can be placed in the formation in order to stimulate production utilizing electrical currents. Alternatively, a thermal element can be located within the wellbore which elevates the formation temperature, resulting in increased production, in particular in fields which have hydrocarbon deposits which tend to congeal and clog the flow pathways and wellbore.
The present invention is also directed to environmental clean-up operations of both subsurface and surface locations. In the prior art, considerable amounts are expended to contain and clean-up undesirable contamination which may reside in a subterranean or surface location. Contaminates may include extremely hazardous materials, such as toxic substances, as well as less hazardous materials such as petroleum based chemicals. Prior art clean-up operations are often very expensive operations to undertake and may involve the excavation, removal, and replacement of surface earth formations. Such projects are of a massive scale, requiring considerable investment of manpower, equipment, and time. For spills that occur in relatively populous regions, there are very few options, since the contaminate soil may present long term hazards to the aquifer or other water supplies adjacent or beneath the contaminated soil. Any improvement in technology that may reduce the investment in dollars, manpower, equipment, and time would be welcome in the industry.